Multiway switches can be used to control load devices, such as lights or electrical fans, in multiple locations. Conventionally, a load device to be controlled is directly connected between multiway switches. However, the shorting of the multiway switches can lead to the shorting of the load device, which in turn, can cause systematic electricity overload. For example, the shorting of the multiway switches can burn a safety fuse of an electricity meter that is connected to the load device or destroy the electricity meter.